Viruses are the source of diseases and other health issues faced by the world's human and animal populations. A wide variety of viral vaccines have been developed to protect these populations. Viral vaccines can include live viruses, attenuated viruses, subunits of viruses, and/or individual molecules to confer protection against a viral infection. Typically, the viral vaccines include at least a portion of the viral particle to induce the recipient of the viral vaccine to develop antibodies against the viral particle to prevent later infection. Viral vaccines have protected large segments of the world's population from infection by viruses. However, viral vaccines are frequently expensive and/or difficult to produce and process on large scales. Therefore, a need exists for apparatus and methods that improve various aspects of viral vaccine production.
Many viral vaccines can be needed cyclically, such as for example the influenza viral vaccines which are typically required annually before the flu season. Because production can take a considerable amount of time, it can be desirable to produce and store viral vaccine many months before it is needed. However, many viral vaccines can lose efficacy if stored in a usable formulation for a period of months. Therefore, many viral vaccines are dehydrated prior to storage to increase their shelf life and then resuspended prior to use.
Various processes have been used to dry viral vaccines. These processes are typically relatively inefficient and time consuming. The inefficiency and time make the end product more expensive. Further, current processes do not typically permit the continuous production of dried product. This can further increase the cost and time for production of a viral vaccine. Therefore, the need exists for apparatus and methods that may more quickly and efficiently prepare a viral vaccine for storage.
In one prior methodology, viral vaccines can be dehydrated by freeze drying. Freeze drying (also known as lyophilization) is a dehydration process that typically involves freezing the liquid viral vaccine and then reducing the surrounding pressure to sublimate the frozen water into the gas phase, which may be evacuated. After the frozen water has been sublimated and the water vapor evacuated, the end result is a viral vaccine in the dried state.
The process of producing dried viral vaccine by freeze drying typically includes several steps. The process typically begins by placing liquid viral vaccine within one or more vials, with the one or more vials being unsealed. The liquid viral vaccine within the one or more vials is then subjected to the freeze drying process resulting in one or more vials containing dried viral vaccine. After the freeze drying process is complete, the one or more vials may then be exposed to a sterilizing gas and then sealed in vacuum conditions. This results in one or more vials containing sterile dried viral vaccine. Alternatively, following freeze drying, the vials may be sealed and the sealed vials exposed to a radiation source for sterilization. Freeze drying viral vaccine may be a time consuming and energy inefficient process. Freeze drying is typically a batch type process where the liquid viral vaccine in groups of vials is subjected to the freeze drying process. Therefore, a need exists for more efficient methods for producing dried viral vaccine.